Changes in microtubular tau protein after morphine in a cultured human neuroblastoma cell line.

1. Cultured human SH-SY5Y adrenergic neuroblastoma cells were used to examine the action of morphine sulfate on microtubular tau protein. 2. After 48 hr treatment morphine sulfate (200 microM) reduced tau protein in the cytoplasmic (supernatant) fraction of undifferentiated cells, and in the cytoplasmic as well as membrane (pellet) fractions of differentiated cells. 3. A 71% increase (P < 0.05) in total protein in the membrane (pellet) fraction of undifferentiated cells and a 188% increase (P < 0.01) in that of differentiated cells accompanied the decrease in tau protein. 4. A 51% reduction (P < 0.01) in the number of undifferentiated (but not differentiated) cells was seen after this drug (200 microM).

Tau protein after delta-9-tetrahydrocannabinol in a human neuroblastoma cell line.

1. A human neuroblastoma cell line, SH-SY5Y, was used to determine the effects of delta-9-tetrahydrocannabinol (THC) on microtubule-associated tau protein. 2. After 48-hr treatment, THC (10(-9) M) decreased 50 kD tau protein in the cytoplasmic (supernatant) fraction, and in the membrane (pellet) fraction the drug (10(-7) M) also decreased 50 kD tau protein. 3. This reduction in tau protein was accompanied by a 27% reduction (P < 0.05) in the membrane (pellet) total protein after (10(-7) M) THC and a 28% increase (P < 0.02) in cytoplasmic (supernatant) total protein after 10(-9) M THC.

D-lysergic acid reduces microtubule-associated tau protein in SH-SY5Y human neuroblastoma cells.

1. SH-SY5Y, an adrenergic human neuroblastoma cell line, was used to examine the hypothesis that D-lysergic acid (LSD) affects the metabolism of microtubule-associated tau protein, thus affecting microtubule assembly and the transport of neurotransmitters. 2. After 48 hr treatment LSD (10(-5) and 10(-7) M) decreased 50 kDa tau protein in the membrane (pellet) fraction. The drug (10(-5) M) also decreased in the cytoplasmic (supernatant) fraction. 3. This reduction in tau protein was accompanied by a 65% increase (P < 0.05) in total protein after LSD (10(-7) M) in the cytoplasmic fraction.

Helicobacter pylori infection does not reduce the viscosity of human gastric mucus gel.

The mechanism by which Helicobacter pylori undermines host defence mechanisms is unclear. Several in vitro studies using soluble mucins have suggested that H pylori may compromise mucus function. Gastric mucus gel was obtained from 13 H pylori infected patients; six untreated subjects and seven after eradication of the infection. Gastric mucus is a non-Newtonian substance in that its viscosity changes with changing rates of shear, requiring mucus viscosity to be measured in a rotational cone-plate microviscometer. Viscosity was measured at shear rates varying from 1.15 s-1 to 46 s-1. The gastric mucus viscosity was significantly higher in patients infected with H pylori compared with mucus gel obtained after eradication of the infection. The results of our study suggest that the previous studies using in vitro methods involving soluble mucins or its components may have lead to erroneous conclusions about the in vivo interactions of H pylori and gastric mucus gel. The present findings argue against the hypothesis that degradation of gastric mucus by H pylori is important in the pathogenesis of peptic ulcer.

Clarithromycin, tetracycline, and bismuth: a new non-metronidazole therapy for Helicobacter pylori infection.

OBJECTIVE: Metronidazole resistance has become an increasing problem that has limited the usefulness of the original triple therapy. Our objective was to evaluate clarithromycin, a new macrolide compound active against Helicobacter pylori. METHODS: We evaluated a new clarithromycin triple therapy for H. pylori infection consisting of the combination of clarithromycin (500 mg t.i.d.), tetracycline (500 mg q.i.d.), and bismuth subsalicylate tablets (2 q.i.d.) for 14 days. Patients with ulcer also received concomitant ranitidine, 300 mg after the evening meal, for 6 wk. RESULTS: Thirty men with documented H. pylori infection were studied; 29 had peptic ulcer disease. Seven had previously failed antimicrobial therapy, including three with metronidazole-based triple therapy. H. pylori status was determined by histology. H. pylori status and ulcer status were evaluated 4 wk after the end of antimicrobial therapy. The ulcer was healed in 90%. The H. pylori infection was cured in 93%, including all three patients who previously failed metronidazole-based triple therapy. CONCLUSION: We conclude that the combination of clarithromycin, tetracycline, and bismuth is an effective new therapy for treatment of H. pylori infection.

Treatment of Helicobacter pylori reduces the rate of rebleeding in peptic ulcer disease.

BACKGROUND: We evaluated whether therapy designed to eradicate Helicobacter pylori infection resulted in a reduction in rebleeding in patients with peptic ulcer disease. Patients presenting because of major upper gastrointestinal hemorrhage from peptic ulcer and whose ulcers healed in a study in which they were randomized to receive ranitidine alone or triple therapy plus ranitidine were followed up regularly with endoscopy. No maintenance anti-ulcer therapy was given after ulcer healing. METHODS: Patients received ranitidine, 300 mg, or ranitidine plus triple therapy. Triple therapy consisted of tetracycline, 2 g; metronidazole, 750 mg; and bismuth subsalicylate, 5 or 8 tablets (151 mg bismuth per tablet), and was administered for the first 2 weeks of treatment; ranitidine therapy was continued until the ulcer had healed or 16 weeks had elapsed. After ulcer healing, no maintenance antiulcer therapy was given. Development of ulcer recurrence with or without recurrent upper gastrointestinal bleeding was evaluated. RESULTS: Thirty-one patients with major upper gastrointestinal bleeding from peptic ulcer were studied; 17 received triple therapy and 14 ranitidine alone. Major rebleeding occurred significantly (p = 0.031) more often in those in the ranitidine group (28.6%), compared with none (0%) in the triple therapy group. CONCLUSION: Eradication of H. pylori infection reduces the rate of ulcer recurrence and rebleeding in complicated ulcer disease.

Changes in microtubular tau protein after estrogen in a cultured human neuroblastoma cell line.

1. Cultured human SH-SY5Y neuroblastoma cells were used to determine whether 17-beta-estradiol affects the metabolism of microtubular tau protein. 2. After 24-hr treatment 17-beta-estradiol (10(-7) M) increased 50 kDa tau protein in the cytoplasmic (supernatant) fraction and decreased it in the membrane (pellet) fraction. 3. The increase in cytoplasmic tau was accompanied by increases in total protein in both cytoplasmic and membrane fractions, 50 and 70%, respectively. 4. The estrogen (10(-7) M) also caused a 31% reduction in the total number of cells.

Gastric mucosal hydrophobicity and Helicobacter pylori: response to antimicrobial therapy.

The hydrophobic properties of the gastric mucosa are reduced by NSAIDs and by Helicobacter pylori infection. Our investigation was to determine whether this abnormality was due to the bacteria or to the inflammatory response. Contact angle measurements were made on gastric antral and corpus biopsies taken from 10 H. pylori-infected volunteers before eradication therapy, after 2 and 14 days of therapy, and 4 weeks after therapy. The contact angle improved steadily and statistically throughout the 2 weeks of therapy (for day 0, 3, 14, respectively) antral mucosa 54.2 +/- 2, 59.3 +/- 2, and 63.2 +/- 2; corpus mucosa 55 +/- 1, 57.8 +/- 3, and 66.6 +/- 1. After 2 days of therapy, H. pylori bacteria were no longer evident, and yet the contact angle continued to improve, suggesting that bacteria and bacterial products (e.g., lipases) may not be critical factors. H. pylori was eradicated in five and failed in five. One month after ending therapy, the contact angles of those with recrudescence of infection and those with eradication were similar and higher (p < 0.05) than before therapy (antrum: 69.8 +/- 1 vs. 71.1 +/- 2, corpus: 66.4 +/- 4 vs. 70.8 +/- 2) (p > 0.25 for both). We conclude that gastric surface hydrophobicity abnormalities do not appear to be directly related to the presence of H. pylori organisms or the histologic features of acute inflammation, but are responsive to antimicrobial therapy.

Helicobacter pylori infection and exaggerated gastrin release. Effects of inflammation and progastrin processing.

Helicobacter pylori infection is associated with exaggerated gastrin release. We investigated whether this abnormality was due to the bacteria or the immune response. Fasting and meal-stimulated 'total' and amidated gastrin were measured in 10 H. pylori-infected volunteers before eradication therapy, after 2 and 14 days of therapy, and 4 weeks after completion of therapy. The exaggerated meal-stimulated gastrin concentration remained unchanged after 2 days of therapy, although the polymorphonuclear cell infiltrate and H. pylori bacteria were no longer evident. The expected fall in gastrin concentration after 14 days of therapy was associated with a reduction in the density of mucosal mononuclear cells, suggesting exaggerated gastrin release was related to chronic inflammation or to H. pylori or its products. The effect of H. pylori on normal progastrin processing was also assessed; 2 control groups were included: 10 H. pylori-uninfected volunteers and 13 patients with H. pylori peptic ulcers. There was a significant difference in the proportion of circulating gastrins that were biologically active amidated gastrins between ulcer patients and uninfected controls (56.7 +/- 4% versus 33.8 +/- 4%, p < 0.001). The proportion of amidated to total gastrins did not increase after successful eradication.

Antral G-cell and D-cell numbers in Helicobacter pylori infection: effect of H. pylori eradication.

BACKGROUND: It has recently been recognized that Helicobacter pylori infection is associated with abnormalities in the regulation of gastrin secretion. We investigated whether there was a relationship between H. pylori infection and G-cell and D-cell numbers. METHODS: The numbers of antral G cells and D cells were compared between 20 patients with duodenal ulcer and 24 volunteers, 12 with and 12 without H. pylori infection. The effect of eradication of H. pylori infection on G-cell number was also evaluated. Antral mucosal biopsy specimens were examined using immunohistochemical techniques specific for the presence of gastrin and somatostatin. RESULTS: The number of G cells was significantly (P < 0.02) less in patients with duodenal ulcer than in either infected or uninfected controls (3.7 +/- 0.3 vs. 6.2 +/- 0.6 and 5.3 +/- 0.5 G cells per gland for infected and uninfected controls, respectively). The ratio of G-cells to D-cells was similar in duodenal ulcer patients (2.2) and uninfected controls (2.0). It was found that, although eradication of the H. pylori infection results in a dramatic reduction in stimulated gastrin secretion, it is not associated with a change in the numbers of antral G cells or D cells in patients with duodenal ulcer. CONCLUSIONS: It is concluded that H. pylori infection-associated increase in gastrin secretion appear to be related to local factors regulating G-cell function.

Changes in the gastric mucosa following eradication of Helicobacter pylori.

Although most studies reporting on the examination of Helicobacter pylori infection have focused on the clearance of the bacteria and the rapid disappearance of the neutrophil infiltrates, the evolution of inflammatory and architectural changes in the antral and corporal mucosa following the eradication of H. pylori has not been addressed systematically. This study examines in detail the histopathologic appearance of the antral and corporal mucosa in a group of patients infected with H. pylori and follows the spectrum of morphologic changes in each of them after the eradication of the infection. At least 11 biopsies ("gastric mapping") were obtained from the antrum and body of each of 15 patients with H. pylori. Complete mapping was then repeated 1, 4, and 10 to 12 mo after the eradication of H. pylori by a course of "triple therapy." Each biopsy was assessed in a semi-quantitative fashion for presence of H. pylori, neutrophils, eosinophils, lymphocytes, lymphoid follicles, and intestinal metaplasia. Other features (integrity of surface epithelium, architecture, fibrosis) were evaluated descriptively. Results were compared with those obtained from a control group of 16 uninfected, healthy adult volunteers. H. pylori infection was eradicated in 11 subjects. The disappearance of neutrophils and the normalization of the surface epithelium closely paralleled that of H. pylori. Persistence of even small numbers of neutrophils was a predictor of relapse. Eosinophils and lymphocytes decreased slowly and did not return to normal levels within 1 yr. Lymphoid follicles decreased very slowly in all patients but were still present in all gastric locations at one year after treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Short report: a non-metronidazole triple therapy for eradication of Helicobacter pylori infection--tetracycline, amoxicillin, bismuth.

Triple therapies using bismuth, metronidazole and tetracycline or amoxicillin were the first truly successful anti-H. pylori therapies. Metronidazole resistance has become an increasing problem that has severely limited the usefulness of the original triple therapy. Resistance to tetracycline or amoxicillin has not been reported and both are effective against H. pylori. We therefore tested a new triple therapy consisting of 500 mg tetracycline, 500 mg amoxicillin, and 2 tablets of bismuth subsalicylate each administered four times daily (with meals and at bedtime) for 14 days during treatment with ranitidine 300 mg daily. H. pylori eradication was defined as no evidence of H. pylori one or more months after stopping therapy. H. pylori status was evaluated by a combination of urea breath test and histology. Sixteen patients with H. pylori infection and active peptic ulcers were enrolled. The new triple therapy was successful in only 7 individuals (43%). Metronidazole appears to be critical for the effectiveness of the original triple therapy. An alternative to metronidazole will be required for a new successful triple therapy.

Microtubular tau protein after cocaine in cultured SH-SY5Y human neuroblastoma.

1. SH-SY5Y, a human neuroblastoma cell line, was used as a tissue culture model to examine the hypothesis that cocaine may affect the metabolism of tau protein which stabilizes microtubules and promotes microtubule assembly. 2. Cocaine hydrochloride (10(-9)-10(-3) M) caused dose-dependent reductions in cell number, with 10(-3) M causing 28% reduction after 48 hr. 3. This drug also decreased tau protein (50 Kd) in the cytoplasmic (supernatant) as well as the membrane (pellet) fraction after 48-hr treatment.

Changes in microtubule-associated tau protein in human neuroblastoma cells after phencyclidine.

1. A human neuroblastoma cell line, SH-SY5Y, was used to study the effects of phencyclidine (PCP) on microtubule-associated tau protein, which acts in vivo chiefly to induce the assembly of tubulin and in vitro to promote microtubule polymerization. 2. PCP (1.0 mM) decreased tau protein (50 kD) in the cytoplasmic (supernatant) fraction as well as in the membrane (pellet) fraction. 3. These changes in tau protein were accompanied by decreases of 30-95% in cell number after concentrations of PCP, 0.25-1.0 mM, respectively. 4. After 0.5 mM PCP cytoplasmic and membrane fractions of SH-SY5Y cells showed 100 and 84% increases in total protein, respectively.

Effect of treatment of Helicobacter pylori infection on the long-term recurrence of gastric or duodenal ulcer. A randomized, controlled study.

OBJECTIVE: To determine the effect of treating Helicobacter pylori infection on the recurrence of gastric and duodenal ulcer disease. DESIGN: Follow-up of up to 2 years in patients with healed ulcers who had participated in randomized, controlled trials. SETTING: A Veterans Affairs hospital. PARTICIPANTS: A total of 109 patients infected with H. pylori who had a recently healed duodenal (83 patients) or gastric ulcer (26 patients) as confirmed by endoscopy. INTERVENTION: Patients received ranitidine, 300 mg, or ranitidine plus triple therapy. Triple therapy consisted of tetracycline, 2 g; metronidazole, 750 mg; and bismuth subsalicylate, 5 or 8 tablets (151 mg bismuth per tablet) and was administered for the first 2 weeks of treatment; ranitidine therapy was continued until the ulcer had healed or 16 weeks had elapsed. After ulcer healing, no maintenance antiulcer therapy was given. MEASUREMENTS: Endoscopy to assess ulcer recurrence was done at 3-month intervals or when a patient developed symptoms, for a maximum of 2 years. RESULTS: The probability of recurrence for patients who received triple therapy plus ranitidine was significantly lower than that for patients who received ranitidine alone: for patients with duodenal ulcer, 12% (95% CI, 1% to 24%) compared with 95% (CI, 84% to 100%); for patients with gastric ulcer, 13% (CI, 4% to 31%) compared with 74% (44% to 100%). Fifty percent of patients who received ranitidine alone for healing of duodenal or gastric ulcer had a relapse within 12 weeks of healing. Ulcer recurrence in the triple therapy group was related to the failure to eradicate H. pylori and to the use of nonsteroidal anti-inflammatory drugs. CONCLUSIONS: Eradication of H. pylori infection markedly changes the natural history of peptic ulcer in patients with duodenal or gastric ulcer. Most peptic ulcers associated with H. pylori infection are curable.

Factors influencing the eradication of Helicobacter pylori with triple therapy.

Helicobacter pylori infection has been associated with gastritis, duodenal ulcer, gastric ulcer, and the epidemic form of gastric carcinoma. Eradication of H. pylori infection has proven to be difficult. Recently, combinations of antimicrobial drugs have been shown to eradicate greater than 50% of infections; however, the results have proven variable, and the factors influencing effectiveness of therapy are unclear. In the present study, the effectiveness of a triple therapy for eradication of H. pylori infection was evaluated. Triple therapy consisted of 2 g tetracycline, 750 mg metronidazole, and five or eight tablets of bismuth subsalicylate daily in 93 patients (70 with duodenal ulcer, 17 with gastric ulcer, and 6 with simple H. pylori gastritis). Combinations of a sensitive urea breath test, serology, culture, and histology were used to confirm the presence of infection, eradication, or relapse. Eradication was defined as inability to show H. pylori greater than or equal to 1 month after ending therapy. The overall eradication rate was 87%. The factors evaluated for their effect on predicting eradication included age, gender, type of disease, duration of therapy, amount of bismuth subsalicylate [five or eight Pepto-Bismol tablets daily (Procter & Gamble, Cincinnati, OH)], and compliance with the prescribed medications. Stepwise regression showed that compliance was the most important factor predicting success; the success rate was 96% for patients who took greater than 60% of the prescribed medications and 69% for patients who took less. For those taking greater than 60% of the prescribed therapy, the eradication rates were similar (a) for patients receiving therapy for 14 days or when tetracycline and bismuth subsalicylate were taken for an additional 14 days; (b) for patients with duodenal ulcer, gastric ulcer, and simple H. pylori gastritis; and (c) whether five or eight bismuth subsalicylate tablets were taken. It is concluded that triple therapy is effective for eradication of H. pylori and that future studies need to take compliance into account for comparisons between regimens.

Effect of triple therapy (antibiotics plus bismuth) on duodenal ulcer healing. A randomized controlled trial.

OBJECTIVE: To determine whether antimicrobial therapy for Helicobacter pylori infection accelerates the healing of duodenal ulcers. DESIGN: Single-blind, randomized, controlled trial. SETTING: Veterans Affairs hospital. PARTICIPANTS: One hundred and five patients with endoscopically verified duodenal ulcers. INTERVENTION: Patients received either ranitidine, 300 mg/d, or ranitidine, 300 mg/d, plus "triple therapy" (2 g/d of tetracycline, 750 mg/d of metronidazole, and 5 or 8 bismuth subsalicylate tablets per day). Triple therapy was administered for only the first 2 weeks of ulcer treatment. MEASUREMENTS: Videoendoscopic assessment of ulcer status was done until ulcer healing was complete. Evaluations were done after 2, 4, 8, 12, and 16 weeks of therapy. MAIN RESULTS: Ulcer healing was more rapid in patients receiving ranitidine plus triple therapy than in patients receiving ranitidine alone (P less than 0.01). The cumulative percentages of patients with healed ulcers in the group receiving ranitidine plus triple therapy and in the group receiving ranitidine alone were as follows: 37% and 18% after week 2; 74% and 53% after week 4; 84% and 68% after week 8; 96% and 80% after week 12; and 98% and 84% after week 16. CONCLUSION: Combined therapy with anti-H. pylori agents and ranitidine was superior to ranitidine alone for duodenal ulcer healing. Our results indicate that H. pylori plays a role in duodenal ulcer disease.

Helicobacter pylori-associated exaggerated gastrin release in duodenal ulcer patients. The effect of bombesin infusion and urea ingestion.

Recent studies have shown that the exaggerated meal-stimulated gastrin release in patients with duodenal ulcer abates after eradication of Helicobacter pylori infection. Bombesin-stimulated gastrin release was compared in 11 H. pylori-infected patients with chronic duodenal ulcer and 8 uninfected healthy volunteers both before and after therapy to eradicate H. pylori. Bombesin infusion significantly increased the gastrin release both in control subjects and in patients with duodenal ulcer. Antimicrobial therapy (bismuth, tetracycline, and metronidazole) to eradicate the H. pylori infection was associated with a significant reduction in bombesin-stimulated gastrin release in patients with duodenal ulcer (from 116.9 +/- 19 pg/mL to 69.5 +/- 7 pg/mL following 50 pmol.kg-1.h-1 bombesin; and from 158 +/- 29 to 83.4 +/- 10 following 200 pmol.kg-1.h-1 bombesin: P = 0.01 for each). Antimicrobial therapy had no effect on gastrin release in uninfected volunteers, thus excluding a nonspecific effect of antimicrobial therapy on antral G-cell function. Serum gastrin was also not increased by feeding 500 mg of urea to 5 H. pylori-infected volunteers. This suggests that access of hydrogen ion to the pH-sensitive sites governing gastrin release by mucosal ammonia produced by H. pylori urease is not a critical factor. These data suggest that exaggerated gastrin release present in patients with duodenal ulcer disease is secondary to H. pylori infection.

Effects of serotonin on tyrosine hydroxylase and tau protein in a human neuroblastoma cell line.

The direct effects of the neurotransmitter serotonin on the catecholaminergic enzyme, tyrosine hydroxylase and the microtubule-associated tau protein were studied in a human neuroblastoma cell line. Undifferentiated LAN-5 cells, cultured in serum supplemented basal medium, or cells induced to differentiate by 6 day exposure to 10 uM retinoic acid were treated for 48 hr with 50 nM and 50 uM serotonin. In undifferentiated cells, serotonin treatment (50 uM) decreased both tyrosine hydroxylase activity and a 50 kD cytoplasmic fraction tau protein while 50 nM serotonin treatment caused this 50 kD protein to increase in the cytoplasmic fraction but decrease in the membrane fraction. While basal tyrosine hydroxylase activity increased in differentiated vs. undifferentiated cells, serotonin treatment had no effect on the enzyme or tau in differentiated LAN-5. This study shows serotonin to have direct effects on the biochemistry and cytoskeleton of undifferentiated cultured human neuroblastoma.

Ablation of exaggerated meal-stimulated gastrin release in duodenal ulcer patients after clearance of Helicobacter (Campylobacter) pylori infection.

An exaggerated increase in meal-stimulated gastrin is a common finding in patients with duodenal ulcer. Duodenal ulcer patients also exhibit an increase in the number of parietal cells, which results in an increase in maximum acid output. There are also data to suggest that acid hypersecretion may not predate the ulcer disease, but is acquired, possibly due to the trophic effects of the exaggerated gastrin release on parietal cells. We investigated meal-stimulated gastrin release in nine Helicobacter pylori-infected individuals; eight patients with chronic duodenal ulcer and one H. pylori-infected healthy control, both before and after therapy designed to eradicate H. pylori infection. We also simultaneously measured intragastric pH in six duodenal ulcer patients. Eradication of the H. pylori infection reversed the exaggerated meal-stimulated gastrin release (gastrin secretion fell from 141 + 16 pg/ml/h before treatment to 98 +/- 7 pg/ml/h after, p less than 0.01) without affecting intragastric pH. Whereas exaggerated meal-stimulated gastrin release may be an important pathogenetic feature of duodenal ulcer disease, we conclude that it is secondary to the H. pylori infection. This study provides further insight into the role of H. pylori in the pathogenesis of duodenal ulcer disease. We postulate that reversal of the abnormalities in gastrin secretion will be associated with a gradual return of gastric secretion to normal.